I was going to asign a rider to my horse but the manage your horse menu has disapeared.

Link to horse page: https://horseeden.com/horse.php?id=22854603

The horse is 100% mine and isn't for sale. I need this solved soon so I can train him.

No matter how many times I log out and back in, won't change

Black Creek is my other acount. Forgot I wasn' t signed in :P

I just tried again but won't change

This horse is owned by your account Wild Dragon Meadows - which is obviousely visible on his page.

This is why you can not manage him from your account Black Creek.

You have to make sure first, which account you are logged into before you think that there is a bug or glitch in the game.

All your "problems" are definitely no bugs, sorry.